Young and middle-aged adults who use marijuana could be at a higher risk for serious heart problems, according to new research.

"A new study says exposure to marijuana may increase the risk of heart complications in some users. People with pre-existing heart problems were more prone to the effects of marijuana." (Via The Weather Channel)

Researchers looked at medical data that was gathered from 2006 - 2010 from a database called the French Addictovigilance Network. (Via Journal of the American Heart Association)

And of the nearly 2,000 reported complications linked to marijuana use, the researchers found that 35 cases, or 2 percent, involved heart problems of some kind. Those cases included 20 heart attacks and nine deaths. (Via Wikimedia Commons / Bogdan)

According to the study's authors, most of the patients were men in their mid-30s. (Via YouTube / MarijuanaCash Crop)

But they also noted many of the patients had other risk factors for heart disease, including drinking alcohol and smoking tobacco. (Via Wikimedia Commons / Tomasz SienickiFlickr / Ken Johnson)

Now, considering the fact that over a million people reportedly smoke marijuana regularly in France, LiveScience points out the number of complications seems pretty small.

But the study's authors say they believe the number of heart-related complications and deaths among marijuana users is actually higher than their research suggests because many incidents aren't reported. A cardiologist told CBS he agrees.

"As more and more marijuana is being used, there have been more identified cases of cardiovascular complications. It can increase heart rate, and this can increase the demand for oxygen by the heart."

​Some doctors say the study's findings could be a warning sign as the U.S. continues to move in the direction of widespread marijuana legalization. (Via Flickr / Torben Hansen)

"Not enough emphasis is being put on the fact that this is an active chemical. What is it doing to people? Are we going to see more complications when it's legal than less? I'm afraid yes, because the education isn't there." (Via Fox News)

But even the study's authors say this research isn't the final word on the link between marijuana and heart problems.

The Huffington Post notes doctors aren't even sure how marijuana affects the cardiovascular system or if it affects people with pre-existing heart conditions differently.

But one thing the researchers are sure about — more studies on the subject need to be done before they can come to a solid conclusion. This study was published Wednesday in the Journal of the American Heart Association.